we have now implemented custom domain names. Its currently under beta testing, but you can already try it if it works. Use now your own domain name with TrashMail. Simply check out the Web-Address-Manager and click on "Account"->"Add custom domain name".

Haven't tried to send anything yet. I was merely checking to see the reputation of the MX server I've put on my domain, so when the time comes to reply to someone, I will be sure that my email will reach him without a problem. As some of the people I mail to, use SpamAssassin (that checks for SORBS), I thought it would be nice to mention it here, just in case something can be done.

I understand the problem. If you can log into SORBS through the blocked IP, you can easily unblock it. We usually use command line lynx browser through the blocked server, to access SORBS and delist. It's a PITA but it's doable if you have access and time to do it.